北京官厅水库轮虫群落结构与水体富营养化状况

Relationship between eutrophication status of the water body and rotifer community structure in Guanting Reservoir,Beijing

于2007年1-12月对官厅水库上游(北京段)进行调查,利用非生物环境因子对水体的营养状况进行了评价,并通过种类组成、优势种、生物量及多样性指数等指标探讨了轮虫群落结构与水体富营养化的关系.结果表明,官厅水库(北京段)已达到了富营养的水平,在轮虫的种类组成中,10个富营养化的指示种类大部分都有出现,其中螺形龟甲轮虫(Keratella cochlearis)和针簇多肢轮虫(Polyarthra trigla)为优势种;轮虫密度均在1000ind./L以上,生物量在1mg/L以上,轮虫的密度、生物量的季节分布与水温显著正相关(P<0.05),水平分布与水体的营养状况显著正相关(P<0.05),垂直分布没有明显的规律性;轮虫多样性指数较低,但与水体营养水平显著相关(P<0.05).证明轮虫群落结构与水体富营养化之间存在着密切的关系,富营养化是导致轮虫群落结构变化的主要动因.

In the present study we evaluated the trophic state of Guanting Reservoir （Beijing part）. The results indicated that the water in Beijing part of Guanting Reservoir had been in eutrophication. According to the data associated with species composition, dominant species, density, biomass and diversity of rotifers, the relationships between rotifer community structure and eutrophication were evaluated. The results indicated that ten key rotifer species for eutrophication appeared regularly and typically in Guanting Reservoir, and the dominant rotifer species were Keratella cochlearis and Polyarthra trigla that annual density and biomass were over 1000ind./L and 1mg/L, respectively. There was significant positive correlations between water temperature and seasonal distribution of density and biomass of rotifers （ P 〈 0. 05 ）. A significant positive correlation was detected between level distribution of rotifers and status of eutrophication （ P 〈 0.05 ）. However, there was no obvious vertical distribution pattern of rotifer species in sample sites of Guanting Reservoir. The level of diversity in rotifer species was not high; however, a significant correlation was found between the level of diversity and status of eutrophication. Our results indicated that there was consanguineous correlation between rotifer community structure and eutrophication, and moreover the eutrophication is main reason causing the change of rotifer community structure.